OLEDs are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic light emitting devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. In addition, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants, while it may be more difficult to tune inorganic emissive materials.
OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly popular technology for applications such as flat panel displays, illumination, and backlighting. OLED configurations include double heterostructure, single heterostructure, and single layer, and a wide variety of organic materials may be used to fabricate OLEDs. Representative OLED materials and configurations are described in U.S. Pat. Nos. 5,707,745, 5,703,436, 5,834,893, 5,844,363, 6,097,147 and 6,303,238, which are incorporated herein by reference in their entirety.